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-rw-r--r--arch/x86/include/asm/e820/api.h5
-rw-r--r--arch/x86/include/asm/pci_x86.h2
-rw-r--r--arch/x86/kernel/resource.c25
-rw-r--r--arch/x86/pci/acpi.c93
-rw-r--r--arch/x86/pci/common.c8
5 files changed, 125 insertions, 8 deletions
diff --git a/arch/x86/include/asm/e820/api.h b/arch/x86/include/asm/e820/api.h
index e8f58ddd06d9..5a39ed59b6db 100644
--- a/arch/x86/include/asm/e820/api.h
+++ b/arch/x86/include/asm/e820/api.h
@@ -4,6 +4,9 @@
#include <asm/e820/types.h>
+struct device;
+struct resource;
+
extern struct e820_table *e820_table;
extern struct e820_table *e820_table_kexec;
extern struct e820_table *e820_table_firmware;
@@ -43,6 +46,8 @@ extern void e820__register_nosave_regions(unsigned long limit_pfn);
extern int e820__get_entry_type(u64 start, u64 end);
+extern void remove_e820_regions(struct device *dev, struct resource *avail);
+
/*
* Returns true iff the specified range [start,end) is completely contained inside
* the ISA region.
diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index 1307cd689d2a..f52a886d35cf 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -42,6 +42,8 @@ do { \
#define PCI_ROOT_NO_CRS 0x100000
#define PCI_NOASSIGN_BARS 0x200000
#define PCI_BIG_ROOT_WINDOW 0x400000
+#define PCI_USE_E820 0x800000
+#define PCI_NO_E820 0x1000000
extern unsigned int pci_probe;
extern unsigned long pirq_table_addr;
diff --git a/arch/x86/kernel/resource.c b/arch/x86/kernel/resource.c
index 9b9fb7882c20..db2b350a37b7 100644
--- a/arch/x86/kernel/resource.c
+++ b/arch/x86/kernel/resource.c
@@ -1,4 +1,5 @@
// SPDX-License-Identifier: GPL-2.0
+#include <linux/dev_printk.h>
#include <linux/ioport.h>
#include <asm/e820/api.h>
@@ -23,16 +24,27 @@ static void resource_clip(struct resource *res, resource_size_t start,
res->start = end + 1;
}
-static void remove_e820_regions(struct resource *avail)
+void remove_e820_regions(struct device *dev, struct resource *avail)
{
int i;
struct e820_entry *entry;
+ u64 e820_start, e820_end;
+ struct resource orig = *avail;
+
+ if (!(avail->flags & IORESOURCE_MEM))
+ return;
for (i = 0; i < e820_table->nr_entries; i++) {
entry = &e820_table->entries[i];
-
- resource_clip(avail, entry->addr,
- entry->addr + entry->size - 1);
+ e820_start = entry->addr;
+ e820_end = entry->addr + entry->size - 1;
+
+ resource_clip(avail, e820_start, e820_end);
+ if (orig.start != avail->start || orig.end != avail->end) {
+ dev_info(dev, "clipped %pR to %pR for e820 entry [mem %#010Lx-%#010Lx]\n",
+ &orig, avail, e820_start, e820_end);
+ orig = *avail;
+ }
}
}
@@ -43,9 +55,6 @@ void arch_remove_reservations(struct resource *avail)
* the low 1MB unconditionally, as this area is needed for some ISA
* cards requiring a memory range, e.g. the i82365 PCMCIA controller.
*/
- if (avail->flags & IORESOURCE_MEM) {
+ if (avail->flags & IORESOURCE_MEM)
resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);
-
- remove_e820_regions(avail);
- }
}
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 052f1d78a562..a4f43054bc79 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -8,6 +8,7 @@
#include <linux/pci-acpi.h>
#include <asm/numa.h>
#include <asm/pci_x86.h>
+#include <asm/e820/api.h>
struct pci_root_info {
struct acpi_pci_root_info common;
@@ -19,6 +20,7 @@ struct pci_root_info {
#endif
};
+static bool pci_use_e820 = true;
static bool pci_use_crs = true;
static bool pci_ignore_seg;
@@ -41,6 +43,14 @@ static int __init set_ignore_seg(const struct dmi_system_id *id)
return 0;
}
+static int __init set_no_e820(const struct dmi_system_id *id)
+{
+ printk(KERN_INFO "PCI: %s detected: not clipping E820 regions from _CRS\n",
+ id->ident);
+ pci_use_e820 = false;
+ return 0;
+}
+
static const struct dmi_system_id pci_crs_quirks[] __initconst = {
/* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */
{
@@ -135,6 +145,51 @@ static const struct dmi_system_id pci_crs_quirks[] __initconst = {
DMI_MATCH(DMI_PRODUCT_NAME, "HP xw9300 Workstation"),
},
},
+
+ /*
+ * Many Lenovo models with "IIL" in their DMI_PRODUCT_VERSION have
+ * an E820 reserved region that covers the entire 32-bit host
+ * bridge memory window from _CRS. Using the E820 region to clip
+ * _CRS means no space is available for hot-added or uninitialized
+ * PCI devices. This typically breaks I2C controllers for touchpads
+ * and hot-added Thunderbolt devices. See the commit log for
+ * models known to require this quirk and related bug reports.
+ */
+ {
+ .callback = set_no_e820,
+ .ident = "Lenovo *IIL* product version",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "IIL"),
+ },
+ },
+
+ /*
+ * The Acer Spin 5 (SP513-54N) has the same E820 reservation covering
+ * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
+ * See https://bugs.launchpad.net/bugs/1884232
+ */
+ {
+ .callback = set_no_e820,
+ .ident = "Acer Spin 5 (SP513-54N)",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Spin SP513-54N"),
+ },
+ },
+
+ /*
+ * Clevo X170KM-G barebones have the same E820 reservation covering
+ * the entire _CRS 32-bit window issue as the Lenovo *IIL* models.
+ * See https://bugzilla.kernel.org/show_bug.cgi?id=214259
+ */
+ {
+ .callback = set_no_e820,
+ .ident = "Clevo X170KM-G Barebone",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_NAME, "X170KM-G"),
+ },
+ },
{}
};
@@ -145,6 +200,27 @@ void __init pci_acpi_crs_quirks(void)
if (year >= 0 && year < 2008 && iomem_resource.end <= 0xffffffff)
pci_use_crs = false;
+ /*
+ * Some firmware includes unusable space (host bridge registers,
+ * hidden PCI device BARs, etc) in PCI host bridge _CRS. This is a
+ * firmware defect, and 4dc2287c1805 ("x86: avoid E820 regions when
+ * allocating address space") has clipped out the unusable space in
+ * the past.
+ *
+ * But other firmware supplies E820 reserved regions that cover
+ * entire _CRS windows, so clipping throws away the entire window,
+ * leaving none for hot-added or uninitialized devices. These E820
+ * entries are probably *not* a firmware defect, so disable the
+ * clipping by default for post-2022 machines.
+ *
+ * We already have quirks to disable clipping for pre-2023
+ * machines, and we'll likely need quirks to *enable* clipping for
+ * post-2022 machines that incorrectly include unusable space in
+ * _CRS.
+ */
+ if (year >= 2023)
+ pci_use_e820 = false;
+
dmi_check_system(pci_crs_quirks);
/*
@@ -160,6 +236,17 @@ void __init pci_acpi_crs_quirks(void)
"if necessary, use \"pci=%s\" and report a bug\n",
pci_use_crs ? "Using" : "Ignoring",
pci_use_crs ? "nocrs" : "use_crs");
+
+ /* "pci=use_e820"/"pci=no_e820" on the kernel cmdline takes precedence */
+ if (pci_probe & PCI_NO_E820)
+ pci_use_e820 = false;
+ else if (pci_probe & PCI_USE_E820)
+ pci_use_e820 = true;
+
+ printk(KERN_INFO "PCI: %s E820 reservations for host bridge windows\n",
+ pci_use_e820 ? "Using" : "Ignoring");
+ if (pci_probe & (PCI_NO_E820 | PCI_USE_E820))
+ printk(KERN_INFO "PCI: Please notify linux-pci@vger.kernel.org so future kernels can this automatically\n");
}
#ifdef CONFIG_PCI_MMCONFIG
@@ -299,6 +386,12 @@ static int pci_acpi_root_prepare_resources(struct acpi_pci_root_info *ci)
int status;
status = acpi_pci_probe_root_resources(ci);
+
+ if (pci_use_e820) {
+ resource_list_for_each_entry(entry, &ci->resources)
+ remove_e820_regions(&device->dev, entry->res);
+ }
+
if (pci_use_crs) {
resource_list_for_each_entry_safe(entry, tmp, &ci->resources)
if (resource_is_pcicfg_ioport(entry->res))
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 9e1e6b8d8876..ddb798603201 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -595,6 +595,14 @@ char *__init pcibios_setup(char *str)
} else if (!strcmp(str, "nocrs")) {
pci_probe |= PCI_ROOT_NO_CRS;
return NULL;
+ } else if (!strcmp(str, "use_e820")) {
+ pci_probe |= PCI_USE_E820;
+ add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
+ return NULL;
+ } else if (!strcmp(str, "no_e820")) {
+ pci_probe |= PCI_NO_E820;
+ add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
+ return NULL;
#ifdef CONFIG_PHYS_ADDR_T_64BIT
} else if (!strcmp(str, "big_root_window")) {
pci_probe |= PCI_BIG_ROOT_WINDOW;
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-19 22:22:31 +0100